Process of making zinc chloride



Feb, 12 9 W24. 1,483,852 7 I ROSENSTEIN PROCESS OF MAKING ZINC CHLORIDESaluli'on ATTORNE Y.

Patented Feb. 12, 1924.

. UNITED STATES PATENT OFFICE.

LUDWIG ROSENSTEIN, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR TO GREAT WEST-ERIN ELECTRO CHEMICAL COMPANY, A CORPORATION OF CALIFORNIA.

PROCESS OF MAKING ZINC CHLORIDE.

Application filed January 31, 1921. Serial No. 442,833.

T all who m it may concern:

Be it known that I, Lunwrc RoSENsTEIN,

a citizen of the United States, residing at San Francisco, in the countyof San Francisco, State of California, have invented a new and usefulProcess of Making Zinc Chloride, of which the following is aspecification in such full and clear terms as will enable those skilledin the'art to construct and use the same.

This invention relates to a process of producing zinc chloride, and itsobject is to produce an extremely pure article-rapidly and economicallyfrom zinc and chlorine.

Many attempts have'been made to produce zinc chloride directly, but whenpure zinc is used the chlorine acts on it rapidly only in the presenceof Water, and then tends to produce zinc chloride containing anindefinite form of zincoxychloride, zinc hypochlorite, zinc chlorate andfree chlorine, all. of which are exceedingly undesirable impurities.

In the formation of zinc chloride from chlorine and zinc there isliberated about 113,000 calories of heat and the present process makesuse of this heat to expedite the process and to aid in producing asolution of the required density, while other processes have absorbedand disposed of this heat by circulating an excessive amount of water. YI

The development of this process shows that a small amount of some othersubstance must be added, which ma act as a catalyst, to the zinc to makethe 'esired reaction go on as it should to produce a pure zinc chloride.The element lead is here used for this purpose in quantities varyingfrom ito 1%, although the precise percentage is not material to theinvention. Tin acts in the same way as lead. v y

he effect of the added substance is to hasten the reaction enormouslyand to produce a zinc chloride practically free from other chlorinecompounds in a solution of any desired strength.

Another ob'ect of the invention is to sup ply the chlorlne to the zincin such a manner as to prevent the chlorine from acting thereon sorapidly as tofuse a solid mass of zinc. This is accomplished bysupplying the chlorine all around a column of the fine zinc particles.

Other objects of the invention will ap pear as the description proceeds.

In the drawings there is illustrated a form of apparatus for carryingout the process, in which the same reference numeral is applied to thesame portion throughout, al-

though it will be understood by those which the zinc is thrown and intowhich water is discharged from the faucet 8.

At the bottom of the chimney there is ia'rger pipe 9 suitably connectedto the lower pipe 7 to produce a gas chamber around the lower end of thepipe 7. The gas chamber produced between the pipe 9 and pipe 7 is forthe purpose of causing the chlorine gas to be fed to the pipe 9'from allsides thereof, since only when the solution within the pipe 9 has beenpushed down to the level of the bottom of the pipe 7 will the gas beable to attack the particles of zinc in the chimney, and then they willescape into the chimney around its entire peripshery.

ounted on supports 12 and 13 is a reto 1% of lead added! water' sprayinto a finely divided form 1 which is charged into the pipe 5 until thechimney is completely filled.

Water is then added until the tank 1 1 is nearly filled. Thereupon' thechlorine is allowed to pass into the chimney and as it does so .itforces the solution down around the pipe 7 so that it attacks the zincall around. The chlorine reacts with the .zinc lead alloy to producezinc chloride without the undesirable compounds mentioned, and with noloss, of chlorine. The lead gradually accumulates in the bottom of thetank and it may be scraped out from time to time.

The water is allowed to run in only as fast as may appear necessary totake off at the faucet 15 a solution of the desired density, the greatheat developed causing all the surplus water to go oil as steam. Thetemperature re ulation is aimed to be such that the zinc c lorideproduced can be collected in the water used withoutturning all of thewater used into steam and without heating the stack so hot as is likely.to melt the zinc, while the density of the solution produced dependsentirely upon the wish of the person operating the stack. If a saturatedsolution is to be made, the Water is allowed to drip in slowly enough tocause most of it to evaporate down to the point where chlorine is likelyto escape, whereas messsa if a weaker solution is desired a considerableexcess of water is allowed to pass through the stack. 7

Experiment shows that the process cannot be worked with pure zinc,because the solutions obtained always contain considerable amounts ofthe impurities mentioned, and because the absorption of chlorine is sosluggish as to prevent commercial success.

What I claim is as follows:

A process of producing zinc chloride which comprises maintaining acolumn of zinc particles in a receptacle open at the top and bottom,maintaining a supply of solution to cover the bottom of receptacle,feedin the chlorine to the material to be treated from the entireperiphery of said column of material.

In testimony whereof I have hereunto set my hand this 6th day ofJanuary, A. D.

LUDWIG ROSENSTEIN.

